Some
mothers do have 'em!

I don't know about that one
specifically. It might be a relative of a very similar one, "Some mothers do have
'em!," discussed by Paul Beale, quoting other authors, in his revision of Eric
Partridge's "Dictionary of Catch Phrases":

"An old Lancashire saying popularised
by Jimmy Clitheroe in radio's 'The Clitheroe Kid', which ran from 1958 to 1972.
. . . Later, as 'Some Mothers Do 'Ave 'Em', the title of Michael Crawford's TV
series. . . . The 'Don't some mothers 'ave 'em!" version was familiar also in
Yorkshire."